New compounds from ballota hispanica. X-ray crystal and molecular structure of hispanonic acid methyl ester (MEAH)

1980 ◽  
Vol 21 (13) ◽  
pp. 1273-1274 ◽  
Author(s):  
J. López de Lerma ◽  
S. García-Blanco ◽  
J.G. Rodríguez
Keyword(s):  
Molecular Structure ◽  
Methyl Ester ◽  
Crystal And Molecular Structure ◽  
Acid Methyl Ester ◽  
X Ray ◽  
Acid Methyl ◽  
New Compounds

scholarly journals Azukisapogenol Triterpene Glycosides from Oxytropis chiliophylla Royle

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2448
Author(s):  
Jun Wang ◽  
Hongshuai Yang ◽  
Yang Liu ◽  
Kelsang Norbo ◽  
Kewu Zeng ◽  
...  
Keyword(s):  
Methyl Ester ◽  
Glucuronic Acid ◽  
Acid Methyl Ester ◽  
Triterpene Glycosides ◽  
Raw 264.7 Cells ◽  
No Production ◽  
Acid Methyl ◽  
Potent Inhibition ◽  
New Compounds ◽  
First Time

Eight azukisapogenol triterpene glycosides, including five new compounds, oxychiliotriterpenosides A–E (1–5), two new methyl glucuronide derivatives that proved to be artifacts, oxychiliotriterpenoside E-glucuronic acid methyl ester (6) and myrioside B-glucuronic acid methyl ester (7), and a known one, myrioside B (8), was isolated from the aerial part of Oxytropis chiliophylla Royle. Their structures were elucidated based on extensive spectroscopic analyses and chemical methods. Triterpene glycosides were first obtained from O. chiliophylla, and those containing a galactose unit (1, 2, 5 and 6) and diglucosidic or triglucosidic linkage at C-29 (1–4), were reported from Oxytropis species for the first time, which might be recognized as a chemotaxonomic feature of O. chiliophylla. All isolated compounds were evaluated for their anti-inflammatory activities against NO production using lipopolysaccharide (LPS)-induced RAW 264.7 cells, but no compounds showed potent inhibition on NO production.

Stereochemistry and Tautomerism of Amino Acid Antagonists: α,γ-Diketo Acids and Esters and their Cyclisation Products

1983 ◽  
Vol 38 (2) ◽  
pp. 220-225 ◽  
Author(s):  
W. S. Sheldrick ◽  
W. Trowitzsch
Keyword(s):  
Amino Acid ◽  
Methyl Ester ◽  
Glyoxylic Acid ◽  
Acid Methyl Ester ◽  
Acid Ethyl Ester ◽  
Enolic Form ◽  
X Ray ◽  
Acid Methyl ◽  
Acid Proton ◽  
Amino Acid Antagonists

Abstract X-ray structural analyses of two α,γ-diketo esters and one α,γ-diketo acid, which are amino acid antagonists, have shown them all to be present in the solid state in the α,β-unsaturated γ-keto enolic form. The structures of the esters β-acetyl-pyruvic acid methyl ester (1) and 2-oxo-cyclopentyl-glyoxylic acid ethyl ester (3) are stabilized by intra-molecular O···H(-O) hydrogen bonds involving the enol proton. In the case of camphor oxalic acid (4) an intramolecular O···H-O hydrogen bond between the γ-keto oxygen and the acid proton is observed. The bond lengths and angles in 1 indicate a significant contribution from the mesomeric β,γ-unsaturated enol form. For comparison purposes the structure of the γ-enol methyl ether of 1, (4-methoxy-2-oxo-pentene)carboxylic acid methyl ester (2) has also been determined. The X-ray structures of the cyclization products of respectively an α,γ-diketo acid and an α,γ-diketo ester are reported.

scholarly journals Micro-focused X-ray diffraction characterization of high-quality [6,6]-phenyl-C61-butyric acid methyl ester single crystals without solvent impurities

2013 ◽  
Vol 1 (36) ◽  
pp. 5619 ◽  
Author(s):  
Giuseppe Paternò ◽  
Anna J. Warren ◽  
Jacob Spencer ◽  
Gwyndaf Evans ◽  
Victoria García Sakai ◽  
...  
Keyword(s):  
Methyl Ester ◽  
Single Crystals ◽  
Butyric Acid ◽  
Acid Methyl Ester ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Acid Methyl ◽  
Butyric Acid Methyl Ester
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